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Frontiers
Antarctic Research: It's Cool!
May 1997
It comes as no surprise that Antarctica is a haven
for glaciologists and snow experts. The frozen continent also draws astronomers
and astro-physicists who like the clear skies and nights that last six
months. Geologists and climatologists are intrigued by the well-preserved
remnants of the past. And oceanographers gather information about the
water that flows beneath the floating ice shelves and sea-ice.
What does come as a surprise to some is the amount of biological research
that takes place at the NSF-funded research stations. Human researchers
adapt to temperatures of 32 o F to -100 o F by importing
warm coats, portable housing and food. Bacteria, plants and animals, however,
adapt biologically.
What is also surprising is the number of researchers who leave their
warm homes to go there, not just willingly, but eagerly. They say the
science explored on the Ice, as the researchers refer to it, is like no
other. While in Antarctica, scientists live for their research -- and
the research is far from routine.
Antarctica is a place where scientists dive below the ice sheet to follow
penguins and seals. They set up tents on ice floes that can break apart
with little notice. They deal with problems of recording data when their
pens freeze at -4 o F. They adjust telescopes when the O-rings
shatter in the cold. And they gain the muscles needed to drill tens of
feet into the ice for samples.
Antarctica is not a place for the faint of heart.
It is impossible to mention all of the projects going on in the three
NSF-funded year-round research centers. What follows is just a glimpse
of a few of the hundreds of studies taking place at the coldest place
on Earth.
Ice Cores Hold Earth's Climate
As ice forms, gasses and other materials are trapped
in the layers that build up over time. This makes Antarctica practically
a time machine. With more than 500,000 years of snow and ice accumulation,
paleoclimatologists find the ice sheet an ideal place to set up their tubular
drills, extract cores and read the history.
What they're discovering is that Earth's climate is not stable,
and never has been. Ice ages are punctuated by interglacial periods
of relative warmth -- such as the one we're currently in. The
interglacial periods have been marked by sudden shifts in temperature,
wind patterns and sea levels. "Some of these rapid changes occur
in two decades," says Paul Mayewski, a glaciologist from the
University of New Hampshire and a 30-year veteran of Antarctic
research. "Some [of the changes in patterns] actually start in
less than two years." While he finds these dramatic shifts surprising,
he also notes that Antarctic cores are in sync with the climate
data found in the ice cores from Greenland.
Mayewski and his colleagues learn about these changes by examining
the chemical indicators, such as seasalt, within the cores. High
seasalt levels signal increased storminess and stronger winds.
In addition, measurements of oxygen isotopes reveal cooling during
periods of increased seasalt. Other tests probe for indicators
of wind patterns, volcanic activity and sea level.
Researchers studying the world's deepest core have differentiated
more than four ice ages, or about 400,000 years of history. Working
in the center of Antarctica's ice sheet, near the Russian base
of Vostok, the team of scientists from the United States, Russia
and France expect ultimately to drill through a total of two
miles of ice, or at least 500,000 years of Earth's past. But
they may have to stop short. Radar images show that their site
is located above a body of fresh water about the size of Lake
Ontario. They plan to drill to 150 feet above the lake, and then
stop so as not to contaminate it.
The site where Mayewski's team works is closer to the sea. The
evidence of rapid climate changes is stored in the cores there,
he says, just as it is in the Greenland Ice Sheet core. However,
in neither case have the scientists found clearly defined causes
of the rapid changes. "We need to understand how these changes
work in order to make a better assessment of natural climatic
change," he says, "and a better assessment of the human impact
on the future climate."
Diving Below the Ice: The Life of Emperors
On the other side of the glass in Gerry Kooyman's observation
chamber, Emperor penguins whiz through the water, their torpedo-like
shapes giving them a grace of movement denied to them on land.
Kooyman, from the Scripps Institution of Oceanography, and his
colleagues have learned that penguins are virtual diving machines,
descending to depths of up to 2,700 feet, spending as much as
20 minutes underwater, resurfacing and diving again.
The birds are the most visible of the continent's native
fauna. Their stamina for cold and ability to dive have brought
Kooyman back for 30 seasons of study. He's become such a fixture
that his colleagues named a mountain after him.
When Kooyman began his work, there was no equipment built
specifically for the study of penguins. Today, the research
team -- which includes Kooyman's sons -- uses many pieces
of equipment adapted and designed for penguin studies. The
divers, for example, work in an aptly named anti-leopard
seal cage to avoid becoming protein for the aggressive seals.
While Kooyman wants to know about the tuxedo-clad birds'
lifestyle, he is also interested in their physiology. How
do these birds metabolize oxygen as they quickly descend
to enormous depths, and then equally quickly ascend? This
behavior would kill humans. How do the penguins withstand
cold of 100 o below zero F? Understanding these
capabilities may ultimately translate to human medical advances.
Researchers are keeping a close eye on the Emperors because
they may be one of the indicator species for global change.
Penguins are dependent on Antarctica's ice for their home
and, to a certain extent, on a shrimp-like zooplankton, called
krill, for their food. Changes in the ice and the plankton
populations will affect the birds quickly. Gerald Kooyman
will be one of the people watching.
At Home In The Ice
In Antarctica, the sea-ice temperature
dips down to -4 o F, a cold place to start a garden.
Yet, inside the collection of crystallized water and salty
brine, algae live, photosynthesize and grow.
At first, no one believed the algae actually lived in the surface layer
of sea-ice, says oceanographer Diane Stoecker of Horn Point Environmental
Laboratory-part of the University of Maryland system. Most people thought
the algae, known as dinoflagellates, were accidentally trapped when the sea-ice
froze. But Stoecker and her colleagues have proven that algae make themselves
at home in one of the coldest and saltiest places on Earth. Furthermore,
in doing so, the algae effectively shade the plants and animals that live
below, and their brown color may affect the melting of the sea-ice.
Far from enduring a hardship, the sea-ice-dwelling algae actually have a
good deal, Stoecker says. "The algae get the sun long before the other microbes
in the water; they have almost no competition and they're protected."
In early spring, algae located within four inches of the surface start to
grow through photosynthesis. Then, before the sea-ice breaks up for the summer,
the algae go dormant, forming protective cysts. With the ice breakup, some
of the algae become plankton food. Other parts float away, safe until the
next growing season.
In addition, Stoecker's studies are showing that the algae have a role in
global climate. When eaten, the algae release a gas that becomes dimethyl
sulfide in the atmosphere. This gas is important as a nucleus for formation
of water droplets that form clouds.
Other Projects on the Ice
- Carbon and Climate in the Southern Ocean.
Led by Robert Anderson of Columbia University and Walker Smith of
the University of Tennessee, researchers are examining the role of
the Southern Ocean in the global carbon cycle and ultimately expect
to use the information to predict the ocean's response to climate change.
As the southern component of the decade-long Joint Global Ocean Flux
Study (JGOFS), the effort includes 13 cruises, some of which will focus
on phytoplankton blooms in the Ross Sea and the role of these phytoplankton
in the global carbon cycle.
- AMANDA Expands Its Neutrino Search.
The Antarctic Muon and Neutrino Detector Array (AMANDA)
makes use of the continent's ice sheet to detect subatomic
particles that may hold clues to activities going on inside
and outside of our own galaxy. Physicists explain that
subatomic particles may indicate distant galactic disturbances,
such as supernovas. In the first nine months of observation,
AMANDA spotted many particles that seem to be evidence
of neutrinos, one type of subatomic particle. Last season,
researchers added six new detectors to the four already
working.
- More Favorite Martians?
Last summer the news startled everyone: A meteorite from
Mars may contain fossils of early life. This news drew
the spotlight to the Antarctic Search for Meteorites, and
to Allan Hills, where the famous meteorite, ALH84001, was
found. During this last November-January research season
(Antarctica's summer), researchers continued the search
for Martian rocks, concentrating on Allan Hills and other
Antarctic locations.
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